1. Field of the Invention
The present invention relates generally to the field of electronic surveillance systems. More specifically, it relates to a system and method for tracking data recorded at various locations on a plurality of video tapes recorded by a video tape recorder as part of a surveillance system.
2. Discussion of the Prior Art
Video surveillance systems are commonly used in airports, casinos, stores and factories in order to monitor a large number of locations simultaneously. Such systems typically include a plurality of video cameras, video monitors for displaying the outputs of the video cameras and devices for remotely controlling the video cameras. More sophisticated video surveillance systems may include a computer for controlling the various components from a remote location. A detailed description of such a video surveillance system is contained in copending United States patent application Ser. No. 08/166,599 which is incorporated herein by reference.
It is also common for such video surveillance systems to include one or more video tape recorders for recording the outputs of the video cameras. The recording of the output of any particular video camera in the system may be triggered by a security operator or by the occurrence of an alarm event such as a break-in or the operation of a timer. In any event, during the course of monitoring large premises such as casinos or airports, it is possible for a large number of events to be recorded on many video cassettes.
In order to keep track of the contents of video cassettes in surveillance systems of the prior art, the operator had to keep a log of the location, on each video cassette, of video tape segments containing particular pieces of information. For example, when recording of a segment of a particular video tape in the system commenced, it was customary for the operator to make a note of the time and date of the recording, the tape count at the start of the recording or a description of the recorded event so that the segment of the tape could be retrieved at a later time. The operator also would make a note of the video cassette being used. A log of the contents of the cassette could thus be developed. In order to view any particular segment of a video tape, the operator had to search the entries in the log to find the data identifying the recorded event. The corresponding tape count and hence the desired tape segment could then be found. Alternatively, the tape could be played back and fast forwarded or rewound until the desired segment was found. It was therefore very cumbersome to keep track of the contents of a large number of events recorded on various video cassettes in a video surveillance system.
The present invention is therefore directed towards providing a method and apparatus for logging and retrieving information on video cassettes used in a surveillance system.